Thank-you guys for all the great answers. Any of these suggestions would work. Probably the cheapest way is a Trick-l-start. That Magnum Combiner really looks like a good solution too for $120 or so. It may not be a huge problem since the first time it failed (batteries 6+ years old) I jumped it off with my Jeep toad. And that's because I then found out the Trombetta relay was bad--no parallelling. And I could have jumped it off itself except it seemed safer to keep all sparks out of the battery bay.
Thank-you again.
Pete
